DIY Chiller Idea

[flanque]

Hello,

Since I cannot justify $650 AUD for a chiller my mission was set to create an inexpensive chiller. All these prices are in AUD.

Refer to the attached picture.

Basically if I purchase one of these (http://www.latestbuy.com.au/portable_mini_fridge.html) for $60, purchase a pump that pushes at around 300L per hour (approximate - your suggestions on this would be great) for $25 and then some hosing for around $30 and a sealed plastic water container for $15, then with a little bit of time and planning I could get a chiller that chills to 20-25C for around $130.

It'll also look good too and not so dodgy as an old scabby bar fridge. Best of all there's a temp controller and it can heat too so if my heater dies during the cooler months then I have a backup plan.

What are your thoughts?

[flanque]

Does anyone have any feedback on this? I think it should work but am not entirely sure.

Thx.

[exodus]

That sounds like a great idea - much better than simply putting coils inside a fridge. The water should help to cool it even more, if the fridge has enough power to keep the water cool.

[flanque]

Well I recon it would because the fridge is rated to cool to 24C. I guess the only thing to be aware of is that the cooling componentry of the fridge would be always be working its backside off until the whole tank reaches 26C and from then onwards it would just be maintaining the temp.

Perhaps if you had a larger capacity fridge it'd be easier on the motor.

It'd be neat if we could set up a donation fund on this forum so that someone can trial agreed upon projects to see if they work or not.

The benefit for everyone else is that they can see with little financial exposure if these ideas do work.

[SCFatz]

I think it would work great.The water will do a better job of heat transfer then just cold air.Metal tubing (although I'm not sure what kind) would also facilitate better temp transfer as well.

How hard the motor has to work will be directly dependent how much cooling is transfered to the water in the tubing....given that thats the only temp lost (not opening the door like a regular fridge) it may not be as bad as you think.

The faster the water in the tubing the less time for temp transfer so the returning water will be warmer the faster it goes,slower will mean cooler...but just for the return water,the impact on the tank will the same either way.
One thing that would mean cooler water (fast or slow) is more tubing,which is more surface area which means more temp transfer.

I think a great idea and should work well.I would not hesitate to try it if money were an issue and my tank was too warm.

[RogerMcAllen]

I am not sure if your picture implies this, but the more water you have in your fridge the better. The increased thermal mass will keep the temp more stable and reduce the work load on your fridge.

[BillD]

Interesting concept, but I suspect that it will be unable to keep up with the demand. You forgot to add a timer to turn it off for the required rest period. It would seem to be relatively economical to operate. I saw no mention of an included 12 volt power supply. It is not an actual refrigeration unit, so it will only cool to a temp relative to ambient. Still, I like to see people that are thinking out side the box. I would be looking for a used water fountain with a refrigeration unit, as the base for what you want to do.

[greenmaji]

It depends on your heat load, most refigerators are not charged and tuned to handle the heat load's that most reefkeepers need.
This can lead to stress on the compressor and or poor performance.

The condensor on the back of the refigerator is passive, put a big fan on it if you try this out. It should help quite a bit :P


*edit* I just re-read and saw mention of this being a TEC frig... improving perfomance will be a pain

I have some ideas though :P

[roka64]

Would the water become stagnant?

[greenmaji]

Originally Posted by roka64

Would the water become stagnant?

probibly, but its not in the loop so you could use aditives to prevent this.